Means for cooling current limiting reactors



Oct. 30, 1945. L, E. SAUER 2,387,947

MEANS FOR COOLING CURRENT LIMITING REACTORS Filed Feb. 27, 1945 Eyz 25 7 1 /3 v 5 I 7 i 24' 4 6 6 I4 24 1 2/ 22 7 2/ f a e 92 /3 Q o 0 Q O O f /6 )2 o f 0 m I ,4 R 1 U o T T o O f O o a Q 0 /05 4 fnJU/af/O/J oziz tke rablo' INVENTQR 7 A 00/3 550M871 Z'nru/afxbn 4 Z: 5; 2

ATTORNEYA/ Patented Oct. 30, 1945 MEANS FOR COOLING CURRENT LIMITING REACTORS Louis E. Sauer, Sharon, Pa, assigncr to Westinghouse Electric Corporation, East Pittsburgh, Pa, a corporation of Pennsylvania Application February 27, 1943, Serial No. 477,402

9 Claims.

My invention relates to electrical apparatus including a winding and, particularly, to means for increasing the efiective cooling of electric windings in apparatus, such as current-limiting reactors or the like, mounted with the winding axis positioned Substantially horizontally.

In current-limiting reactors, the several turns of conductor forming the reactor winding are usually" arranged in layers, the turns in each layer being spaced apart. to provide ventilating spaces between them and the layers also being spaced apart, thus allowing free circulation of a cooling medium, such as air, about the individual winding turns. The Winding turns are usually arranged. in the form of a cylinder or annular structure providing a central. opening which is free of obstruction. When the winding is mounted with its axis in a vertical position, this central opening acts as a chimney permitting air heated by the winding conductors to move upwardl and to suck' cooling air into the central space later-ally between the winding turns, which air is heated by the conductors of the turns and passes upwardly through the central opening. The thermal head thus created increases the circulation of air and the cooling of the winding conductors.

In certain cases, as when there is insufficient floor space for mounting the reactor with its Winding axis vertically, it becomes necessary or desirable to mount the reactor with its axis positioned horizontally. When the winding is mounted with its axis in a horizontal position, the central opening does not develop the same chimney effect, and unless some means is provided to prevent it, hot spots tend to develop in the winding for failure of the air to circulate proper1y in the regions on the two opposite sides of the winding. When, therefore, current limiting reactor windings are mounted horizontally to meet space requirements, the radial winding supports usedto retain the individual conductor turns in position, block. the natural flow of the cooling medium around the conductors in the areas above mentioned. The heat generated in these portions of the winding must be conducted along the conductors to a place Where the cooling medium flows freely past the conductor windings. This causes a considerable increase in the hot spot temperature of the winding.

It is an object of my invention to provide means for establishing a definite thermal head on those sections of the winding in which the cooling medium would otherwise be nearly stagnant to thus efiect a circulation of the cooling medium in this area by thermal action.

More particularly, I provide chimneys and baffles to guide the flow of air past the side portions of the winding.

My invention will be better understood by reference to the accompanying drawing, in which:

Figure 1 is a sectional view taken along the line I--I of Fig. 2 showing a current limiting reactor constructed in accordance with an embodiment of the invention;

Fig. 2 is a side elevational view of the reactor;

and

Fig. 3 illustrates curves.

Referring to the drawing, two disk or annular shaped end members I and 2 are provided which may be formed of reinforced concrete or other insulating material. The end members are mounted upon insulating footings 3 and 4 of porcelain or equivalent insulating material. Tie rods 5 are provided extending between the end members I and 2 and are spaced circumferentially about the edges thereof and extend through openings in stacks of fire-proof cleats 6. The rods 5 hold the parts of the entire structure in their assembled relation. The cleats 6 may be molded from long fiber asbestos and laid layer on layer in each stack so as to support the individual turns of conductor 1. Grooves may be provided in the cleats E to support the conductor turns in a particular layer in a spaced position with respect to each other, and several layers of the winding are spaced from one another b the thickness of the individual cleats, such as the stacks numbered l0, Ii, I2, I3, and I4. These stacks of cleats form radial barriers extending from the outer edge of the winding to the central space surrounded b the winding turns. As indicated by the arrows, the air, when heated by the conductors will rise between these radial barriers at the bottom of the winding, through the central space within the winding, and upwardly between the radial barriers at the top of the winding, to cool the conductors.

On the two opposite sides of the winding, however, in the portion between the radial barriers ii) and i l, the individual barriers extend so nearly in a horizontal direction as to interfere with the free flow of air therebetween. Curved barriers I5 are, therefore, provided positioned as shown and extending between the radial barriers H and I3 so as to guide air coming inwardly between the winding conductors in the passageway between barriers H and E2 upwardly and outwardly through the passage between barriers I2 and I3. A similar barrier it is shown on each side of the winding extending about the barrier l5 and spaced therefrom, and extending between the radial barriers l and Hi to guide cooling air flowing inwardly through the passageway between radial barriers Ill and II upwardly and outwardly through the passageway between the radial barriers l3 and i4.

Chimneys l1 and I8 are provided to increase the upward flow of heated air and induce a suction through the tortuous paths inwardly, upwardly, and outwardly between the windings as the cooling medium passes through the passageways between the radial barriers on opposite sides of the winding. To provide these chimneys, wall 2| is shown extending upwardly from the outer edge of the barrier [2, a wall 22 extends upwardly from the barrier l3, and a wall 25 from the barrier l4. End walls 25 are provided to complete the chimney structure.

The use of the barriers I5 and I6 and of the chimneys extending upwardly creates a definite thermal head to cause a flow of air through those sections of the winding in which the cooling medium would otherwise be stagnant or nearly so. This causes a considerable reduction in the hot spot temperature in the portions of the conductor on the opposite sides of the winding where the conductor is extendin generally in a vertical direction.

In the curves shown in Fig. 3, the vertical axis shows the temperature rise in degrees centigrade, and the'horizontal axis shows the time in hours. The two curves are hot spot temperature curves, that is, they show the temperature of the winding at the hottest part of the wind ing. The curve 26 shows the rise in temperature when the barriers l5 and I6 and the chimneys I l and I8, are not used and the curve 21 shows the'same reactor'with the same current flowing with the baflies l5 and H3 and relatively short chimneys applied. It will be noted that when the barriers and chimneys are not used, the term perature of the winding with normal current flow ing inwardly between adjacent stacks of cleats upwardly and outwardly through a passageway between adjacent stacks of cleats to provid a tortuous path for the cooling medium inwardly and outwardly between the winding turns and in an upwardly direction.

2. In an air core reactor, vertical end members, a plurality of layers of electric conductor disposed between the end members forming a cylindrical winding surrounding a central open space and mounted with its axi positioned horizontally, the saparate winding turns of conductor being spaced apart to permit the free flow of a cooling medium therebetween, a plurality of stacks of cleats positioned between the several layers and extending radially of the winding forming radial barriers spaced about the winding extending between the central space and the outer area about the winding, barriers within the central space positioned to divert a cooling medium passing inwardly between adjacent stacks of cleats upwardly and outwardly through a passageway between adjacent stacks of cleats to provide a tortuous path for the cooling medium inwardly and outwardly between the winding turns and in an upwardly direction, and chimneys extendin upwardly from the space between the upper pairs of barriers to provide a thermal head for increasing the flow of the cooling medium about the circuit conductors.

3. In an air core reactor, vertical end members, a plurality of layers of electric conductor disposed between the end members forming a cylindrical winding surrounding a central open space and mounted with its axis positioned horizontally, the separate winding turns of conductor being spaced apart to permit the free flow of a cooling medium therebetween, a plurality of stacks of cleats positioned between the several layers and extending radially of the winding therein rises much faster and comes to a constant value at a much higher temperature, as indicated by the curve 26 than when the barriers and chimneys are used, in which case the rate of increase in temperature and maximum temperature is indicated by the curve 21. The cooler winding results from the increase in the flow of a cooling medium, such as air past the individual winding turns, thus increasing the rate at which heat is carried from the conductors on the two opposite sides of the winding.

It will be apparent to those skilled in the art that modifications in the structure and arrangements of partsmay be made within the spirit of my invention, and I do not wish to be limited otherwise than by the scope of the appended stack extending radially of the winding formingradial barriers spaced about the winding extending between the central space and the outer area about the winding, barriers within the central space positioned to divert a cooling medium passforming radial barriers spaced about the winding extending between the central space and the outer area about the winding, barriers positioned within the central space within the winding adjacent the two opposite sides thereof to divert a cooling medium passing inwardly between adjacent stacks of cleats approximately in a horizontal direction so as to pass upwardly and outwardly. between conductors of the winding through a passageway between adjacent stacks of cleats.

4. In an air core reactor, vertical end members, a plurality of layers of' electric conductor disposed between the end members forming a cylindrical winding surrounding a central open space and mounted with its axis positioned horizontally, the separate winding turns of conductor being spaced apart to permit the free flow of a cooling medium therebetween, a plurality of stacks of cleats positioned between the several layers and extending radially of the winding forming radial barriers spaced about the winding extending between the central space and the outer area about the winding, barriers positioned within the central space within the winding adjacent the two opposite sides thereof to divert a cooling medium passing inwardly between adjacent stacks of cleats approximately in a horizontal direction so as to pass upwardly and outwardly between conductors of the winding through a passageway between adjacent stacks of cleats, and chimneys extending upwardly from the space between the upper pairs of barriers to provide a thermal head for increasing the flow of the cooling medium about the circuit conductors.

5. In an air core reactor, vertical end members. I

a plurality of layers of electric conductor disposed between the end members forming a cylindrical winding surrounding a, central open space and mounted with its axis positioned horizontally, the separate winding turns of conductor being spaced apart to permit the free flow of a cooling medium therebetween, a plurality of stacks of cleats positioned between the several layers and extending radially of the winding forming radial barriers spaced about the winding extending between the central space and the outer area about the winding, a plurality of barriers on each side of the central space within the winding for diverting a cooling medium passing inwardly between adjacent stacks of cleats so as to direct the incoming medium upwardly and outwardly between winding conductors through passageways between adjacent stacks of cleats, the barriers on the two opposite sides of the central space within the winding turns being sufiiciently spaced from each other to provide a space between them for the free circulation of a cooling medium upwardly between the radial barriers on the lower portion of the winding, between the barriers on the two opposite sides of the winding and between radial barriers on the upper portion of the winding.

6. In an air core reactor, vertical end members, a plurality of layers of electric conductor disposed between the end members forming a cylindrical winding surrounding a central open space and mounted with it axis positioned horizontally, the separate winding turns of conductor being spaced apart to permit the free flow of a cooling medium therebetween, a plurality of radial barriers spaced about the winding for supportin the winding turns in spaced relation to one another, additional barriers within the central space positioned to divert a cooling medium passing inwardly between adjacent radial barspace and mounted with its axis positioned horizontally, the separate winding turns of conductor being spaced apart to permit the free flow of a cooling medium therebetween, a plurality of radial barriers spaced about the winding for supporting the winding turns in spaced relation to one another, additional barriers within the central space positioned to divert a cooling medium passing inwardly between adjacent radial barriers upwardly and outwardly through a passageway between adjacent radial barriers to provide a tortuous path for the cooling medium inwardly and outwardly between the winding turns and in an upwardly direction, and chimneys extending upwardly from the space between the upper pairs of adjacent radial barriers to provide a thermal head for increasing the flow of the cooling medium about the circuit conductors.

8. In an air core reactor, vertical end members, a plurality of layers of electric conductor disposed between the end members forming a cylindical winding surrounding a central open space and mounted with its axis positioned horizontally, the separate winding turns of conductor being spaced apart to permit the free flow of a cooling medium therebetween, a plurality of radial barriers spaced about the winding for supporting the Winding turns in spaced relation to one another, additional barriers positioned within the central space within the winding adjacent the two opposite sides thereof to divert a cooling medium passing inwardly between adjacent radial barriers positioned generally in a horizontal direction so as to guide a cooling medium to pass upwardly and outwardly between conductors of the winding through a passageway between adjacent radial barriers.

9. In an air core reactor, vertical end members, a plurality of layers of electric conductor disposed between the end members forming a cylindrical winding surrounding a central open space and mounted with its axis positioned horizontally, the separate winding turns of conductor being spaced apart to permit the free flow of a cooling medium therebetween, a plurality of radial barriers spaced about the winding for supporting the winding turns in spaced relation to one another, additional barriers positioned within the central space within the winding adjacent the two opposite sides thereof to divert a cooling medium passing inwardly between adjacent radial barriers generally in a horizontal direction so as to guide a cooling medium to pass upwardly and outwardly between conductors of the winding through a passageway between adjacent radial barriers, and chimneys extending upwardly from the space between the upper pairs of barriers to provide a thermal head for increasing the flow of the cooling medium about the circuit conductors.

LOUIS E, SAUER. 

